*{
    padding: 0;
    margin: 0;
}
.layer{
    position: relative;
    width: 1200px;
    height: 460px;
    margin:auto;
    border:1px solid red;
    /* overflow: hidden; */
}
.layer img{
    display:block;
    width: 1200px;
    height: 460px;
}
ul{
    position: absolute;
    right:10px;
    bottom:10px;
    overflow: hidden;
}
ul li{
    list-style:none;
    width: 30px;
    height: 30px;
    font-size: 15px;
    border:1px solid #dedede;
    float: left;
    margin:5px;
    text-align:center;
    line-height: 30px;
    cursor: pointer;
    background-color:rgba(0,0,0,0.3);
    color:red;
}
.active{
    background-color:#fff;
    color:#333;
}